Development of 300 g scintillating calorimeters

The sensitivity for WIMP detection can be improved by an ability to efficiently discriminate the γ and β backgrounds from the nuclear recoil signals. The CRESST phase II detectors will achieve this discrimination by means of simultaneous measurement of phonons and scintillation light. We report on the development of a 300 g detector module consisting of two separate calorimeters fitted with tungsten phase transition thermometers. A 300 g CaWO4 crystal serves as the target material in which a recoiling WIMP creates both phonons and scintillation light. Phonons are detected by a thermometer on the CaWO4 crystal. A second smaller detector in close proximity detects the scintillation light. Measurements with this setup will be presented.